Mills was acquired from the Milwaukee Brewers organization in a minor league trade on Tuesday in exchange for cash considerations. He has spent the entire season at Triple-A Nashville where he went 4-2 with a 1.56 ERA and .190 opponents batting average in 14 games, including 12 starts. His ERA is the lowest in the Pacific Coast League and second lowest among all full season minor leaguers.

The 29-year-old left-hander also ranks third in the PCL in opponents batting average and fourth in strikeouts (77). Mills is 1-2 over his last five starts but has a 0.87 ERA over that span. He made his Major League debut with Toronto in 2009 and last pitched in the majors with the Los Angeles Angels in 2012. Mills is 3-3 with a 7.76 ERA in 15 career appearances, including 10 starts.

Scribner was recalled from Sacramento on Tuesday but did not appear in a game with the A’s. He was on the A’s Opening Day roster and made two scoreless appearances (1.1 ip) before he was optioned to Sacramento April 7. Scribner is 2-1 with nine saves and a 4.32 ERA in 21 relief appearances with the River Cats and has struck out 34 while walking just six in 25.0 innings.